Transformer tilt out trunnion arrangement for enclosed cubicle use



Sept 4, 1962 N. KRr-:EKON ErAL 3,052,820

TRANSFORMER TILT OUT TRUNNION ARRANGEMENT FOR ENCLOSED CUBICLE USE Filed Nov. 28, 1958 f6 j @mf/5% 7 l 30 .5f f? .5 l

United States Patent O 3,652,320 TRANSFORMER TILT GUT TRUNNION ARRANGE- MENT FR ENCLSED CUBICLE USE Nicholas Kreekon, William H. Lane, and Joseph Kotowski, Milwaukee, Wis., assignors to Allis-Chalmers Manufacturing Company, Milwaukee, Wis.

Filed Nov. 28, 1958, Ser. No. 776,814 8 Claims. (Cl. 317-99) This invention relates to enclosed switchboard structures and more particularly to a transformer tilt out trunnion arrangement wherein the electrical connection to the primary circuit of the transformer is disconnected from the electric source before access can be obtained to either the transformer or its primary fuse.

Heretofore potential transformers and fuse arrangements have been disconnected from their electric source of power by a linkage arrangement actuated by the opening of the door of their compartment or by physically moving the transformer and fuse away from their power source. The latter arrangement requires mounting the transformer and fuse on a carriage which would be rolled or slid out of its switchboard compartment. Each of these prior art systems require greater production cost with the possibilities of jamming and fouling. Further, the carriage mounted transformer and fuse arrangement used heretofore requires a considerable amount of drawout space.

In accordance with the invention claimed a new and improved transformer tilt out trunnion arrangement is provided which comprises a pair of electrical contact terminals `disposed inwardly of an access opening of a compartment or enclosure within a switchboard structure. A tilt out carrier having a base is mounted to rotate within the opening from a first position to a second position. The base is arranged to form a barrier between the electrical contact terminals and the access opening in either of its two positions. A transformer having a contact terminal is mounted on the base for rotation therewith and when the base is in the first position makes contact with an electric circuit and when rotated to the second position becomes disconnected from the electric circuit. Means are provided for grounding the transformer at some time when the carrier is rotated from the first position to the second position.

It is, therefore, one object of this invention to provide a new and improved potential transformer arrangement within an enclosed switchboard structure.

Another object of this invention is to provide a new and improved tilt out trunnion arrangement for transformers -mounted within an enclosed switchboard structure. i A further object of this invention is to provide a new and improved potential transformer arrangement for enclosed switchboard structures which requires a space slightly larger than the transformer for physical movement from energized to deenergized positions.

A still further object of this invention is to provide a new and improved ti-lt out trunnion mounting for potential transformers within an enclosed switchboard structure which mounting is provided with an offset center of gravity to insure a firm, positive contact between the transformer and its bus bar `connecti-on and when rotated to disconnect position to insure that the transformer remains in its disconnected position.

Objects and advantages other than those above set forth `wi-ll be apparent from the following description when read in connection with the accompanying drawing, in which:

FIG. l is a side sectional elevational view of a switchboard enclosure with a potential transformer and fuse arrangement in energized position and embodying the invention;

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FIG. 2 is a right end elevational view of the switchboard enclosure and apparatus shown in FIG. l;

FIG. 3 is a side sectional elevational view similar to FIG. l with the potential transformer and fuse arrangement in tilt out position; and

FIG. 4 is a cross sectional view of the structure shown in FIG. 2 taken along the line IV-IV.

Referring more particularly to the drawing by characters of reference FIGS. l-4 illustrate a compartment or enclosure 10 of a control apparatus such as, for example, a switchboard structure. Enclosure 1i) is provided with an opening 1-1 through which access to the inside of the enclosure is obtained. A control panel or base 12 is pivotally mounted by trunnions 13, 13 for rotation within opening 11 and forms a barrier to enclosure 10` in either one of two predetermined positions. Trunnions 13, 13 are supported within notches 14, 14 of mounting brackets 15, 15 which are welded to frame 16 of the switchboard structure forming enclosure 10.

One or more potential transformers and their associated fuses may be mounted on base 12. As shown in the drawing, base 12 has three potential transformers 17, 17 and 17 and electrically associated fuses 18, 18' and 18" mounted thereon in such a manner that when base 12 is in a first predetermined position the transformers and fuses are energized in enclosure 10 and when rotated to a second predetermined position the transformers and fuses are in a deenergized position. Transformers -17, 17 and 17" are so mounted that they have an offset center of gravity, i.e., the transformer assembly is unbalanced. Its center of gravity ldoes not lie in the same vertical plane as do the trunnions 13, 13' of base 12. This type of mounting insures a iirm, positive contact between each of the transformers and their associated bus bars 9, 9' and 9" when energized within enclosures 10 and when deenergized from the bus bars by rotation of base 12 to its second position shown in FIG. 3 insures by means of the shifting of the `center of gravity of the assembly that the transformers remain in their disconnected positions. A folding handle .19 is loosely attached to an extension of base 12 so that an operator can tilt the base and transformer assembly.

As illustrated in the drawing, transformers 17, 17' and 17 are each provided with clips 20 and 21 which serve as holders for fuses `18, 18 and 18". Clips 21 are arranged at one of the terminal ends 23, 23 and 2 of the primary windings of the transformers and in electrical contact therewith while clips 20- are mounted on insulating supports 22, 22 and 22 of these transformers. The other end of the primary winding of these transformers terminate at 24, 24 and 24". Terminal elements 2S, 25 and 25 connected to termina-l clips 20 and insulating supports 22, 22 and 22" of transformers 17, 17 and 17" form electrical contact With the bus bars 9, 9 and 9", respectively.

At some time when pivoted from the energized position shown in FIG. l to the deenergized position shown in FIG. 3 the primary windings of the transformers and their transformer mounted current limiting fuses 18, 18 and 18 are automatically grounded to remove any charge from the windings by metallic clips 20 and 21 at both ends of the fuses and terminal elements 25, 25' and 25 engaging grounding terminals 26, 26 and 26, respectively, which are conductively connected to the frame of the switchboard enclosure.

The terminals of the `secondary windings of the transformers are arranged for connection to a terminal block 34 fixedly mounted on base 12 of the switchboard structure. The stationary wiring is arranged for connection to a plurality of terminal elements 28 which form sliding linger contacts 27 for engaging while in transformer aos-aseo 3 energized position in enclosure with terminal block 34 mounted on base 12.

Rotation of base 12 and the transformers and fuses mounted thereon are limited by barrier wall 2.9 which engages base 12 in its tilt out position. This wall in addition to forming a limit stop also cooperates with base l2 to form a barrier to opening 11 of the enclosure. If vibrations should occur a bolt connection 30 may be provided for more firmly holding and locking the transformers in energized position. An outer door '31 hingedly mounted at 32 on frame 16 completes the switchboard assembly.

With the claimed structure in racked in position operation thereof is as follows:

Door 3l is opened and it pivots at the hinge point 32 exposing the opening 1l of enclosure lil. Opening 11 is blocked vby base l2 and barrier wall 29. The operator then takes hold of handle 19 and pulls the transformer assembly out and down. The transformer assembly pivots on its trunnions y13, 13 in notches 14, 14 of brackets 15, l5 through an angle of approximately 180 degrees or at least more than 90 degrees. At this point the transformer assembly is disconnected, deenergized by grounding and rests against barrier wall 29. Fuses ycan now be removed easily by taking hold of the fuse in one hand and pulling it out of the fuse clips. Because the transformer is disconnected this operation is completely safe. To remove the transformer assembly including Abase l2 from the enclosure the operator merely lifts the unit upward a short distance, about an inch, to lift the trunnions 13, i3 out of grooves 14, lli in brackets l5, l5.

To connect and reenergize the transformer assembly, the operator merely takes hold of the collapsible handle and pulls up and out. The base l2 and the transformer assembly pivots through substantially 180 degrees or at least more than 90 degrees into energized position. During this racking in operation the center of gravity shifts to insure a firm electrical contact between the transformer assembly `and the bus bars. The operator now has the inner `steel barrier formed by base l2 and barrier wall 29 in front of him and between him and the transformer and fuse assembly. Closing the outer door 3i of the enclosure completes the operation.

Thus, in accordance with the invention claimed a new and improved tilt out tinnnion transformer lassembly is provided for enclosed switchboard structures which reduces the number of moving parts thereby greatly reducing or eliminating sticking and binding, utilizes the minimum amount of drawout space, continually keeps one or more barriers between the operator and the bus bar at all times, makes inspection and testing of the transformers and fuses safe `and easy and eliminates all linkage arrangements.

Although 4but one embodiment of the present invention has ibeen illustrated and described it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope yof the -appended claims.

Having now particularly Idescribed and ascertained the nature of our said invention and the manner in which it is to be performed, we decl-are that what we claim is:

l. In combination, an enclosure having an access opening therein, `an electrical Contact terminal disposed Within said enclosure inwardly of said opening, a tilt out carrier comprising a base mounted intermediate the ends of said opening to rotate within said opening from a first position to a second position, said base substantially lilling said opening in either of said positions to form a barrier between said electrical contact terminal and said opening in either of said positions, a transformer comprising a coil having a contact terminal, said transformer being mounted on said base for rotation therewith, said contact terminals of said transformer engaging said elec- CIN ,X trical contact terminal when in said one position and becoming disconnected from said electrical contact terminal when said carrier is rotated to said second position.

2. In combination, an enclosure having an access opening therein, an electrical contact terminal disposed within said enclosure inwardly of said opening, a tilt out carrier comprising a base mounted intermediate the ends of said opening to rotate within said opening from a first position to a second position, said base substantially filling said opening in either of said positions to form a barrier between said electrical contact terminal and said opening in either of said positions, a transformer comprising a coil having a contact terminal, a fuse electrically connected with said transformer and having a contact terminal, said transformer and said fuse being mounted on said -base for rotation therewith, said contact terminals of said transformer and said fuse engaging said electrical contact terminal when in said one position and becoming disconnected from said electrical contact terminals when said carrier is rotated to said second position, and means for grounding said transformer and said fuse at some time when said carrier is rotating from said rst position to said second position.

3. In combination, an enclosure having an access opening therein, a pair of electrical contact terminals disposed within said enclosure inwardly of said opening, a tilt out carrier comprising a base mounted intermediate the ends of said opening to rotate within said opening from a first position to a second position, said base substantially iilling said opening in either of said positions to form a barrier between said electrical contact terminals and said opening in either of said positions, a transformer comprising a coil having a contact terminal, a a fuse electrically connected with said transformer and `having a contact terminal, said transformer and said fuse being mounted on said base for rotation therewith, said contact terminals of said transformer and said fuse engaging said electrical contact terminals when in said one position and becoming disconnected from said electrical contact terminals when said carrier is rotated to said second position, said fuse extending outside of said enclosure through said access opening when said carrier is in said second position and means for grounding said transformer a part of the time While said carrier is rotating from said rst position to said second position.

In combina-tion, an enclosure having an access opening therein, a pair of electrical Contact terminals disposed within said enclosure inwardly of said opening, a tilt out carrier comprising a base mounted intermediate the ends of said opening to rotate within said opening from a iirst position to a second position, said base substantially filling said opening in either of said positions to form a barrier between said electrical contact terminals and said opening in either of said positions, a transformer comprising a coil having a contact terminal, a fuse electrically connected with said transformer and having a contact terminal, said transformer and said fuse being mounted on said base for rotation therewith such that the center of gravity lies in a vertical plane other than the vertical plane passing through said pivotal mounting of said carrier, said contact terminals of said transformer and said fuse engaging said electrical contact terminals when in said one position and becoming disconnected from said electrical contact terminals when said car-rier is rotated to said second position, said fuse extending outside of said enclosure through said access opening when said carrier is in said second position and means for grounding said transformer a part of the time While said carrier is rotating from said first position to said second position.

5. In combination, an enclosure having an access opening therein, la pair of electrical contact terminals disposed within said enclosure inwardly of said opening, a tilt out carrier `comprising a base mounted intermediate the ends of said opening to rotate within said opening from -a first position to a second position, said fbase substantially filling said opening in either of Said positions to form 1a barrier between said electrical contact terminals and said opening in either of said positions, a transformer comprising a coil having `a contact terminal, and a fuse electrically connected with said transformer and having a Contact terminal, said transformer and said fuse being mounted on said base for rotation therewith and in a position such that the center of gravity of said carrier and said transformer lies between said electrical contact terminals and said pivotal mounting of said carrier, said contact terminals of said transformer and said fuse firmly engaging said electrical contact terminals by means of gravity when in said one position land becoming disconnected from said electrical contact terminals and remaining disengaged from said electrical contact terminals by means of gravity when said carrier is rotated to said second position, said fuse extending outside of said enclosure through said access opening when said carrier is in said second position.

6. In combination, ian enclosure having an access opening therein, a pair of electrical contact terminals disposed within said enclosure inwardly of said opening, a tilt out carrier comprising a base mounted intermediate the ends of said opening to rotate within said opening from a first position to a second position, said base substantially filling said' opening in either of said positions to form a barrier ybetween said electrical contact terminals and said opening in either of said positions, a transformer comprising a coil having a contact terminal, a fuse electrically connected with said transformer and having a contact terminal, said transformer and said fuse being mounted on said base for rotation therewith in a position such that the center of gravity of said carrier and said transformer lies between said electrical contact terminals and said pivotal mounting of said carrier, said contact terminals of said transformer and said fuse firmly engaging said electrical contact terminals by means of gravity when in said one position and becoming disconnected from said electrical contact terminals and remaining disengaged from said electrical contact terminals by means of gravity when said carrier is rotated to said second position, said -fuse extending outside of said enclosure through said access opening when said carrier is in said second position, and means for grounding said transformer lat some time when said carrier is rotating from said irst position to said second position.

7. In combination, an enclosure having an access opening therein, a pair of electrical contact terminals disposed Within said enclosure inwardly of said opening, a tilt out carrier comprising a base mounted intermediate the ends of said opening to rotate within said opening from a first position to a second position, said base substantially filling said opening in either of said positions to form a barrier between said electrical contact terminals and said opening in either of said positions, a transformer' `comprising a coil having a contact terminal, said transformer' being mounted on said base in a position such that the center of gravity lies 4between said electrical contact terminals and said pivotal mounting of Said carrier, said contact terminals of said transformer firmly engaging said electrical contact terminals by means of gravity when in said one position and becoming disconnected from said electrical contact terminals and remaining disengaged from said electrical Contact terminals by means of gravity when said carrier is rotated to Said second position, said fuse extending outside of said enclosure through said access opening when said carrier is in said second position, and means for grounding said transformer at some time when said carrier is rotating from said irst position to said second position.

8. In combination, an enclosure having `an access opening therein, a pair of electrical contact terminals disposed within said enclosure inwardly of said opening, a tilt out carrier comprising a base mounted intermediate the ends of said opening to rotate within said opening from a first position to a second position, said base substantially filling said opening in either of said positions to form a barrier between said enclosure and outside thereof in either of said positions, a transformer comprising a coil having a contact terminal, a fuse electrically connected within said transformer and having a Contact terminal, said transformer and said fuse being mounted on said base yfor rotation therewith such that the center of gravity lies in a vertical plane other than the vertical plane passing through said pivot-al mounting of said carrier, said contact terminals of said transformer and said fuse engaging said electrical contact terminals when in said one position `and becoming disconnected from said electrical contact terminals when said carrier is rotated to said second position, said fuse extending outside of said enclosure through said access opening when said carrier is in said second position rand means for grounding said transformer at some time when said carrier is rotating from said first position to said second position.

References Cited in the tile of this patent UNITED STATES PATENTS 1,253,761 Wolfsberg Jan. 15, 1918 1,299,692 Palmer Apr. 8, t1919 2,594,075 Rugg Apr. 22, 1952 2,636,929 Southwick Apr. 28, 1953 2,688,716 Egi'ng Sept. 7, 1954 2,815,410 Pearson Dec. 3, 1957 FOREIGN PATENTS l79771 Great Britain May 18, 1922 

